Abstract

Magnetic shape memory effect or magnetically induced structure reorientation (MIR) occurred down to 1.7 K in 10 M martensite with composition of Ni50.0Mn27.5Ga22.5 exhibiting no intermartensite transformation. The reorientation of the martensite microstructure was mediated by the motion of single Type II twin boundary. In contrast with weak thermal dependence of Type II boundary, MIR with Type I boundary in the same alloy showed strong thermal dependence resembling normal thermal activation process and the effect disappeared below 220 K. Thus the type of the boundary is decisive for MIR at low temperatures.

Received 09 May 2013Accepted 24 July 2013Published online 15 August 2013

Acknowledgments:

We would like to thank Jan Drahokoupil for X-ray determination of lattice parameters and Sebastian Fähler for fruitful discussion about the character of temperature dependence. L.S. acknowledges funding from the Academy of Finland. The work was supported by Czech Scientific Foundation (P107/11/0391) and by the Academy of Sciences of the Czech Republic (M100101241).